Terry A. Junek1, Patricia V. Pietrantonio1, Bradley W. Hopkins1, Ed Bynum2, Manda Cattaneo2, Greg Cronholm2, R.R. Minzenmayer2, Glen Moore2, Dale Mott2, Roy Parker2, C. G. Sansone2, Kerry Siders2, Noel Troxclair2, M. R. Vandiver2, and Jesus Vargas-Camplis3. (1) Texas A&M University, Department of Entomology, MS 2475, College Station, TX 77845-2475, (2) Texas Cooperative Extension, 100 E. Third St., Suite 305B, Sweetwater, TX 79556, (3) Patronato para Investigacion, Fomento y Sanidid Vegetal, Ave. Canada 101, Matamoros, Tamaulipas, Mexico
A monitoring program evaluated the susceptibility of male bollworm, Helicoverpa zea (Boddie), populations to pyrethroid insecticides from April to September, 2007. Twelve Texas counties were surveyed, along with one location in Tamaulipas, Mexico. Moths were trapped near cotton fields using a synthetic pheromone. Glass vials coated with different concentrations of cypermethrin dissolved in acetone were used to assess moth mortality. Data were collected from all collaborators and sent to the Texas A&M University Toxicology Laboratory for analyses, including LC50, LC90, and resistance ratios. Nueces, Uvalde and Williamson Co. populations exhibited the highest LC50 resistant ratios. Burleson County populations displayed high LC50 resistance ratios in April and in July. Populations monitored in other Texas counties and Mexico maintained susceptibility.
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